Approximately 120,000 people in the U.S. alone are waiting for an organ transplant, and there are many more who could benefit from one but haven’t made the list because there simply aren’t enough organs available. But what if the supply could be increased by utilizing the organs of another species? The process is called xenotransplantation, and its what Dr. Joseph Tector and his team have been working on for years now.

As the director of the University of Alabama Xenotransplant Program, Dr. Tector explains the main roadblock to xenotransplantation: rejection by the receiver’s antibodies. However, he and his team have genetically modified pig organs in a way that—in conjunction with immunosuppressant drugs—will decrease or eliminate the human antibody response, thereby preventing rejection. Ten people on the waitlist have already been tested and shown to have no detectable antibodies to the pig cells, making them candidates for transplant.